Revert of [builtins] Introduce proper Float64Exp operator.

src/x64/codegen-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/x64/codegen-x64.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/codegen.h"
 #include "src/macro-assembler.h"
@@ skipping 14 matching lines @@
 void StubRuntimeCallHelper::AfterCall(MacroAssembler* masm) const {
   masm->LeaveFrame(StackFrame::INTERNAL);
   DCHECK(masm->has_frame());
   masm->set_has_frame(false);
 }
 
 
 #define __ masm.
 
 
+UnaryMathFunctionWithIsolate CreateExpFunction(Isolate* isolate) {
+  size_t actual_size;
+  byte* buffer =
+      static_cast<byte*>(base::OS::Allocate(1 * KB, &actual_size, true));
+  if (buffer == nullptr) return nullptr;
+  ExternalReference::InitializeMathExpData();
+
+  MacroAssembler masm(isolate, buffer, static_cast<int>(actual_size),
+                      CodeObjectRequired::kNo);
+  // xmm0: raw double input.
+  XMMRegister input = xmm0;
+  XMMRegister result = xmm1;
+  __ pushq(rax);
+  __ pushq(rbx);
+
+  MathExpGenerator::EmitMathExp(&masm, input, result, xmm2, rax, rbx);
+
+  __ popq(rbx);
+  __ popq(rax);
+  __ Movsd(xmm0, result);
+  __ Ret();
+
+  CodeDesc desc;
+  masm.GetCode(&desc);
+  DCHECK(!RelocInfo::RequiresRelocation(desc));
+
+  Assembler::FlushICache(isolate, buffer, actual_size);
+  base::OS::ProtectCode(buffer, actual_size);
+  return FUNCTION_CAST<UnaryMathFunctionWithIsolate>(buffer);
+}
+
+
 UnaryMathFunctionWithIsolate CreateSqrtFunction(Isolate* isolate) {
   size_t actual_size;
   // Allocate buffer in executable space.
   byte* buffer =
       static_cast<byte*>(base::OS::Allocate(1 * KB, &actual_size, true));
   if (buffer == nullptr) return nullptr;
 
   MacroAssembler masm(isolate, buffer, static_cast<int>(actual_size),
                       CodeObjectRequired::kNo);
   // xmm0: raw double input.
@@ skipping 415 matching lines @@
   // One-byte string.
   // Load the byte into the result register.
   __ bind(&one_byte);
   __ movzxbl(result, FieldOperand(string,
                                   index,
                                   times_1,
                                   SeqOneByteString::kHeaderSize));
   __ bind(&done);
 }
 
+
+void MathExpGenerator::EmitMathExp(MacroAssembler* masm,
+                                   XMMRegister input,
+                                   XMMRegister result,
+                                   XMMRegister double_scratch,
+                                   Register temp1,
+                                   Register temp2) {
+  DCHECK(!input.is(result));
+  DCHECK(!input.is(double_scratch));
+  DCHECK(!result.is(double_scratch));
+  DCHECK(!temp1.is(temp2));
+  DCHECK(ExternalReference::math_exp_constants(0).address() != NULL);
+  DCHECK(!masm->serializer_enabled());  // External references not serializable.
+
+  Label done;
+
+  __ Move(kScratchRegister, ExternalReference::math_exp_constants(0));
+  __ Movsd(double_scratch, Operand(kScratchRegister, 0 * kDoubleSize));
+  __ Xorpd(result, result);
+  __ Ucomisd(double_scratch, input);
+  __ j(above_equal, &done);
+  __ Ucomisd(input, Operand(kScratchRegister, 1 * kDoubleSize));
+  __ Movsd(result, Operand(kScratchRegister, 2 * kDoubleSize));
+  __ j(above_equal, &done);
+  __ Movsd(double_scratch, Operand(kScratchRegister, 3 * kDoubleSize));
+  __ Movsd(result, Operand(kScratchRegister, 4 * kDoubleSize));
+  __ Mulsd(double_scratch, input);
+  __ Addsd(double_scratch, result);
+  __ Movq(temp2, double_scratch);
+  __ Subsd(double_scratch, result);
+  __ Movsd(result, Operand(kScratchRegister, 6 * kDoubleSize));
+  __ leaq(temp1, Operand(temp2, 0x1ff800));
+  __ andq(temp2, Immediate(0x7ff));
+  __ shrq(temp1, Immediate(11));
+  __ Mulsd(double_scratch, Operand(kScratchRegister, 5 * kDoubleSize));
+  __ Move(kScratchRegister, ExternalReference::math_exp_log_table());
+  __ shlq(temp1, Immediate(52));
+  __ orq(temp1, Operand(kScratchRegister, temp2, times_8, 0));
+  __ Move(kScratchRegister, ExternalReference::math_exp_constants(0));
+  __ Subsd(double_scratch, input);
+  __ Movsd(input, double_scratch);
+  __ Subsd(result, double_scratch);
+  __ Mulsd(input, double_scratch);
+  __ Mulsd(result, input);
+  __ Movq(input, temp1);
+  __ Mulsd(result, Operand(kScratchRegister, 7 * kDoubleSize));
+  __ Subsd(result, double_scratch);
+  __ Addsd(result, Operand(kScratchRegister, 8 * kDoubleSize));
+  __ Mulsd(result, input);
+
+  __ bind(&done);
+}
+
 #undef __
 
 
 CodeAgingHelper::CodeAgingHelper(Isolate* isolate) {
   USE(isolate);
   DCHECK(young_sequence_.length() == kNoCodeAgeSequenceLength);
   // The sequence of instructions that is patched out for aging code is the
   // following boilerplate stack-building prologue that is found both in
   // FUNCTION and OPTIMIZED_FUNCTION code:
   CodePatcher patcher(isolate, young_sequence_.start(),
@@ skipping 70 matching lines @@
     return Operand(base_reg_, argument_count_reg_, times_pointer_size,
         displacement_to_last_argument + (receiver - 1 - index) * kPointerSize);
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64